Closed loop control of shifting clutch actuators in an automatic speed change transmission

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(11)

EP 1 433 982 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	11.04.2007 Bulletin 2007/15

(43)	Date of publication A2:
	30.06.2004 Bulletin 2004/27

(21)	Application number: 03028192.7

(22)	Date of filing: 09.12.2003

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International Patent Classification (IPC):

F16H 61/02^(2006.01)
F16H 61/06^(2006.01)
F16H 57/04^(2006.01)

F16H 61/00^(2006.01)
F16H 59/68^(2006.01)

(84)	Designated Contracting States:
	AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR
	Designated Extension States:
	AL LT LV MK

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Priority:

23.12.2002 US 327792

(71)	Applicant: Eaton Corporation
	Cleveland, Ohio 44114-2584 (US)

(72)	Inventors:
	Ford, Greg E. Redford, Michigan 48239 (US) Jacobsen, Peter M. Oakland Township, Michigan 48363 (US) Bowman, Harold L. Lapeer, Michigan 48446 (US)

(74)	Representative: Rüger, Barthelt & Abel Patentanwälte
	Postfach 10 04 61 73704 Esslingen a.N. 73704 Esslingen a.N. (DE)

(54)	Closed loop control of shifting clutch actuators in an automatic speed change transmission

(57) A method of controlling hydraulic shift clutch actuators in an automatic speed change power transmission of the type having an electronic controller (TCU) for energizing a solenoid operated valve to control each hydraulic clutch actuator. A pressure sensor is disposed to sense the hydraulic pressure (P_s) to each clutch actuator and provides an electrical signal to the TCU which also receives a clutch pressure command signal (P_c) from the vehicle powertrain computer. The TCU computes the differential ΔP = P_c - P_s and determines the valve energization current I_E from known relationships between ΔP and the percentage of maximum valve current and repeats the process in real time to adjust I_E until ΔP is negligible.

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